99 research outputs found

    The Role of Bile in the Regulation of Exocrine Pancreatic Secretion

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    As early as 1926 Mellanby (1) was able to show that introduction of bile into the duodenum of anesthetized cats produces a copious flow of pancreatic juice. In conscious dogs, Ivy & Lueth (2) reported, bile is only a weak stimulant of pancreatic secretion. Diversion of bile from the duodenum, however, did not influence pancreatic volume secretion stimulated by a meal (3,4). Moreover, Thomas & Crider (5) observed that bile not only failed to stimulate the secretion of pancreatic juice but also abolished the pancreatic response to intraduodenally administered peptone or soap

    Structural and functional insight into human O-GlcNAcase.

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    O-GlcNAc hydrolase (OGA) removes O-linked N-acetylglucosamine (O-GlcNAc) from a myriad of nucleocytoplasmic proteins. Through co-expression and assembly of OGA fragments, we determined the three-dimensional structure of human OGA, revealing an unusual helix-exchanged dimer that lays a structural foundation for an improved understanding of substrate recognition and regulation of OGA. Structures of OGA in complex with a series of inhibitors define a precise blueprint for the design of inhibitors that have clinical value

    No Adverse Effect of Genetically Modified Antifungal Wheat on Decomposition Dynamics and the Soil Fauna Community – A Field Study

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    The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community

    Potential side effects of biocontrol and plant-growth promoting Bacillus amyloliquefaciens bacteria on earthworms

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    After 1-2 months, survival, growth and reproduction of the earthworms were recorded. We found no effect of the treatments as compared to control without BA amendments. We conclude that the use of high doses of BA with concentrations at the same magnitude as maximally expected when the bacteria are used as PGPR and BCA, is not harmful to the soil dwelling earthworms tested in this project. Further studies of the ecological effects of PGPR and BCA bacteria on other non-target soil organisms are encouraged. The development of sustainable agricultural systems, where ecosystem services are optimized, has to be aided by a deeper knowledge of the combined effect of bacteria and earthworms on the promotion of plant health. (C) 2015 Elsevier B.V. All rights reserved

    Comparison of phenol red and polyethyleneglycol as nonabsorbable markers for the study of intestinal absorption in humans

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    When phenol red and polyethyleneglycol were used simultaneously as nonabsorbable markers in perfusion studies of the absorptive capacity of high jejunum in humans, apparent absorption was the same when calculated from either marker. This similar indication of dilution and of absorption by the two markers was found in normal subjects and in patients with nontropical sprue, whether aqueous or saline solutions of dextrose were infused. The similarity strengthens the evidence that either phenol red or polyethyleneglycol is a satisfactory “nonabsorbable” marker compound to indicate dilution in perfusion studies of dextrose and electrolyte absorption in limited segments of human intestine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44368/1/10620_2005_Article_BF02233070.pd

    Brain Transcriptional Profiles of Male Alternative Reproductive Tactics and Females in Bluegill Sunfish

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    We thank Scott Colborne for his help in collecting bluegill, Dave Bridges for providing the R script to convert Ensemble IDs to stickleback homologs, and David Winter and Jeramia Ory for providing Python script used in the bioinformatics analyses. We thank Doug Haywick for producing Fig 1. We also thank Shawn Garner, Tim Hain, Lauren Kordonowy, and Lindsay Havens, and three anonymous reviewers for helpful comments on the manuscript.Bluegill sunfish (Lepomis macrochirus) are one of the classic systems for studying male alternative reproductive tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three reproductive tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from sneaker to satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male tactics and females during spawning to identify gene ontology (GO) categories and potential candidate genes associated with each tactic. We found that sneaker males had higher levels of gene expression differentiation compared to the other two male tactics. Sneaker males also had higher expression in ionotropic glutamate receptor genes, specifically AMPA receptors, compared to other males, which may be important for increased spatial working memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning.Yeshttp://www.plosone.org/static/editorial#pee
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